In downwell oilfield operations, ports on a tool can be shifted when the tool is downwell. In one example, a gravel pack-circulating sleeve can be used downwell during gravel packing procedures. The sleeve can be shifted between open and closed positions. To shift the sleeve between open and closed positions, a shifting tool can be used to transfer force to the sleeve to shift the sleeve. A sleeve can be fully or partially shifted inadvertently, however, due to accidental bumping or jarring from a shifting tool or another tool downwell, or from movement of the sleeve itself. Full or partial shifting can result in leaks or other costly problems. Partial shifting can cause leaks that damage the sealing elements of the tool over time. In some situations, a fluid leak can increase the difficulty in closing the sleeve after it has been inadvertently opened. Because of the possibility of a sleeve being “bumped” open or closed, it can become difficult to know or assume the correct status of the sleeve downwell. Some sleeves can include a mechanical device that increases the force required to begin shifting the sleeve, but once that force is achieved, the sleeve shifts quickly and easily. Therefore, if the sleeve is quickly bumped enough to overcome the force required to begin shifting the sleeve, the sleeve can remain in a partially shifted state or can shift completely.